// let fp = require('./assets/lodash-fp.min.js')
let fp = require('lodash/fp')
// 数据
// horsepower 马力, dollar_value 价格, in_stock 库存
const cars = [
  {
    name: 'Ferrari FF',
    horsepower: 660,
    dollar_value: 700000,
    in_stock: true
  },
  {
    name: 'Ferrari FF',
    horsepower: 660,
    dollar_value: 700000,
    in_stock: true
  },
  {
    name: 'Spyker C12 Zagato',
    horsepower: 650,
    dollar_value: 648000,
    in_stock: false
  },
  {
    name: 'Jaguar XKR-S',
    horsepower: 550,
    dollar_value: 132000,
    in_stock: false
  },
  {
    name: 'Audi R8',
    horsepower: 525,
    dollar_value: 114200,
    in_stock: false
  },
  {
    name: 'Aston Martin One-77',
    horsepower: 750,
    dollar_value: 1850000,
    in_stock: true
  },
  {
    name: 'Pagani Huayra',
    horsepower: 700,
    dollar_value: 1300000,
    in_stock: false
  },
]


console.log('::::::::练习1')
// let isLastInStock = function (cars) {
//   // 获取最后一条数据
//   let last_car = fp.last(cars)
//   // 获取最后一条数据的 in_stock 属性值
//   return fp.prop('in_stock', last_car)
// }
// console.log(isLastInStock(cars))

// console.log(fp.last(cars))
const last = cars => fp.last(cars)
// console.log(last(cars))
const prop = fp.curry((prop, obj) => fp.prop(prop, obj))
// console.log(prop('in_stock'))
// console.log(prop('in_stock')(last(cars)))
const f = fp.flowRight(prop('in_stock'), last)
console.log(f(cars))


console.log('::::::::练习2')
const first = cars => fp.head(cars)
const prop2 = fp.curry((prop, obj) => fp.prop(prop, obj))
const f2 = fp.flowRight(prop2('name'), first)
console.log(f2(cars))


console.log('::::::::练习3')
// ----FP模块和lodash的函数相比（// 函数置先，数据置后） fp.map(fp.toUpper, ['a', 'b', 'c'])
let _average = function (xs) {
  return fp.reduce(fp.add, 0, xs) / xs.length
} // <- 无须改动
// let averageDollarValue = function (cars) {
//   let dollar_values = fp.map(function (car) {
//     return car.dollar_value
//   }, cars)
//   return _average(dollar_values)
// }
// console.log(averageDollarValue(cars))

let objectProp = fp.curry((value, cars) => fp.map(obj => obj[value], cars))
// console.log(fp.map(obj => obj['dollar_value'], cars))
let getArr = arr => objectProp('dollar_value')(arr)
let f3 = fp.flowRight(_average, getArr)
console.log(f3(cars))


console.log('::::::::练习4')
let _underscore = fp.replace(/\W+/g, '_') // 无需改动,并在sanitizeNames中使用  sanitizeNames(['Hello World']) ==> 'hello_world'

// console.log(_underscore('Hello World'))
// let toLower = str => fp(str)
// let p4 = fp.flowRight(_underscore, toLower)
let map = arr => fp.map(item => fp.toLower(_underscore(item)) , arr)
console.log(map(['Hello World']))



